The present invention relates to hand-carried cases or bags, and more particularly to dual-function foldable cases which, in their open position may be used as a seat with a back-rest, whose use is convenient for the beach and other outdoor activities such as picnics and the like. Still more specifically, the invention concerns a foldable case of the type disclosed in Israel Patent Specification No. 57687 dated June 29, 1979. In this publication there has been disclosed a case comprised of a pair of side wall members each provided with a lower, partly cylindrical portion. The side wall members were connected to each other by rivets or pivot pins. One of the wall members included projecting detents that formed a stop for limiting the amount of the relative rotation of the side walls when used as a seat with a back-rest.
It has been found that since the casing members were made of injected plastic, which is of relatively poor mechanical strength as well as low specific surface pressure capabilities, this design has failed from the mechanical point of view; the hinge connections and the detents could not withstand the stress and surface pressure prevailing during use of the case as a seat.
From the manufacturing point of view, the known case suffered another disadvantage in that the side wall members were not identical and required two, rather expensive injection molds for their production.
It is therefore the object of the present invention to provide a case of the type referred to with an improved hinging or pivoting arrangement of strong and durable construction as required under the operational conditions of the article.
It is a further object of the invention that both side wall members be identical, i.e. be produced by one and the same plastic injection mold.